1. Field of the Invention
The present invention relates to a recording device control apparatus, and in particular to a technique for controlling transfer of data based on transfer requests successively issued by application programs (hereinafter called “applications”) to transfer data to a single recording device.
2. Description of the Related Art
Digital recorders of recent times are capable of processing a plurality of read and write requests with respect to one recording device.
Take for example a case in which television program data is recorded to a hard disk at the same time as data recorded on a DVD (Digital Versatile Disc) is dubbed to the same hard disk. When the file system receives respective write requests from the recording application and the dubbing application, write processing is performed in the following way.
The file system, which holds management information such as file data location information and free-block information, sends file data and management information write requests to the device driver so that synchronization of data and management information written to the hard disk can be achieved.
The device driver writes recording and dubbing data and data of management information to the hard disk in the order requested by the file system.
In this way, even if respective management information of the recording data and the dubbing data is recorded to the same area, inconsistencies in the management information and the like can be avoided as long as the data is written to the device driver in the order sent from file system.
However, the following problem may occur when writing the recording data. Because the television program data is sent and written to the buffer at a fixed transmission bit rate, if there is a delay in writing from the buffer to the hard disk, the buffer capacity may become full with television program data and recording thereof may fail. In view of this problem, a control apparatus has been disclosed for prioritively writing data relating to write requests for recording, where writing to the hard disk cannot be delayed (see Japanese Laid Open Patent Application No. H10-275059, for example).